In a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) time division duplex (TDD) system, one radio frame has a length of 10 ms, and includes 10 subframes. A length of each subframe is 1 ms, and a subframe may be configured by a network side device to transmit downlink data or uplink data. The LTE TDD system supports seven different subframe configurations. In a downlink subframe, a network device may send a downlink data packet to a user equipment; and in an uplink subframe, the user equipment may send an uplink data packet to the network device. In a special subframe, the network device may send a downlink data packet to the user equipment, but the user equipment cannot send an uplink data packet to the network device; therefore, the special subframe is generally also regarded as a downlink subframe.
The 3GPP LTE system is an ever evolving system, and currently, a network device notifies, by using a system broadcast message, a user equipment that which subframe configuration of the seven subframe configurations is used. A change to a subframe configuration is completed by undergoing a process of updating a system message. Considering bursty uplink and downlink services, it is often required that the subframe configuration can be rapidly changed in the case of a relatively small number of users, so as to better match a characteristic of current service traffic. The subframe configuration may often be changed every hundreds of milliseconds, and even be changed every ten milliseconds. A method for dynamically changing the subframe configuration according to an instantaneous service requirement of a user includes: setting, by a base station, at least one downlink subframe, at least one uplink subframe, and at least one dynamic subframe in each radio frame for a user equipment, where each dynamic subframe can be dynamically used for downlink data transmission or uplink data transmission according to a requirement, so as to support dynamic switching between the current seven LTE TDD subframe configurations. A dynamic change to the subframe configuration is mainly applied indoors or applied to small cells covered by hotspots, and such cells generally have a small coverage radius and serve a relatively small number of users.
When a user served in a cell currently has an uplink service, for example, video monitoring, and when a dynamic subframe is used as an uplink subframe for transmitting the uplink service in the prior art, only 60% uplink subframes can be provided, and downlink subframes that account for 40% of a radio frame are idle subframes; and when the user served in the cell currently has a downlink service, for example, file downloading, and when the dynamic subframe is used as a downlink subframe for transmitting the downlink service in the prior art, at most only 90% downlink subframes can be provided, and uplink subframes that account for 10% of the radio frame are idle subframes. Therefore, a method for dynamically changing a subframe configuration in the prior art cannot be better adapted to an uplink-dominated service and a downlink-dominated service, and some subframes cannot be used.